Method of insulating electric wires and cables



(No Model.)

A. W. CORNWALL.

METHOD OF INSULATING ELECTRIC WIRES AND GABLES.

No. 245.352. Patented Aug. 9,1881.

UNITED STATES PATENT OFFICE.

ARTHUR W. CORNWALL, OF BLACK DIAMOND, CALIFORNIA.

METHOD OF INSULATING ELECTRIC WIRES AND CABLES.

SPECIFICATION forming part of Letters Patent No. 245,352, dated August 9, 1881.

Application filed May 27, 1881.

To all whom it may concern.-

Be it known that I, ARTHUR W. CORNWALL, of Black Diamond, county of Contra Costa, State of California, have invented a Method of Insulating Electric WVires and Cables; and I do hereby declare that the following is a full, clear, and exact description thereof.

Myinvention relates to theinsulation ot' telegraph and other wires with asbestos; and it consists in weaving or braiding on the wire a covering of asbestus which has been spun into threads or mixed with other substances, thus wrapping or winding the same, and finally coating it with asbestos paint, so as to hermetically seal the wire within a non-conducting and indestructible casing.

Referring to the accompanying drawing for a more complete description of my invention, the figure shows a wire with its inclosingcasing woven or wound upon it.

An objection tolayingtelegraphwires under ground, where they would be less in the way and better protected, is the difiicolty and expense of insulating them. This I overcome by using threads which are spun from asbestos, and forming a covering for the wire with them. To do this the wire is passed through a machine which may be made to work similarly to a whip-braiding machine, and these threads of asbestos are braided about the wire so as to form a continuous covering. 1 then wind the (No model.)

asbestos threads about the wire, and finally treat the braided and wound wire with a coating of asbestos paint. This renders the wire impervious to moisture and completely inso lates it, so that it maybe laid beneath the surface of the ground, where it will remain without deterioration. When the preparation of the wire has been completed it may be coiled, and will then be ready for use, as its flexibility will not be aifected by the process.

Iain aware that asbestosthreadshave heretofore been braided around wire for the purposes of insulation, and therefore I make no claim to the use of asbestos, broadly, but confine myself to my precise method, as hereinbefore set forth.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

The method of insulating telegraphwires or cables, consisting in first weaving or braiding with asbestos threads, then wrapping or winding with the same, and finally coating with asbestos paint, substantiallyasherein described.

In witness whereof I have hereunto set my hand.

ARTHUR W. CORNWALL.

Witnesses GEO. H. STRONG, S. H. NoURsn. 

